The present invention relates to a new and distinct cultivar of Phlox plant, known as Phlox ‘Rose Sprite’ and will be referred to hereafter by its cultivar name or the “new plant”. The new plant was the result of a cross of Phlox subulata ‘Apple Blossom’ (not patented) as the female or seed parent and an unnamed selection of Phlox procumbens as the male or pollen parent is unknown performed at a wholesale perennial nursery in Zeeland, Mich. on Mar. 31, 2014. The new plant was given the breeder code 14-308-5 prior to naming and throughout subsequent evaluations at the same nursery. ‘Rose Sprite’ has been asexually propagated by stem cuttings in the greenhouses at the same nursery in Zeeland, Mich. since 2016. The unique characteristics of the new plant have been found to be reproducible and stable in successive generations of asexually propagated plants and the resultant plants have been found to be identical to the original selection.